Compensating cam roller



Dec. 17, 1957 w. e. STERZER 2,816,457

COMPENSATING CAM ROLLER Filed Feb. 25, 1954 INVENTOR I WALTER G. STERZER avg HIS ATTORNEYS ice COMPENSATING CAM ROLLER Walter G. Sterzcr, Dayton, Ohio, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Application February 25, 1954, Serial No. 412,520

2 Claims. (Cl. 74-569) This invention relates to a compensating cam roller.

The invention is shown applied to a differential drive mechanism for differentially adjusting the beam in a machine of the class illustrated in United States Patent No. 2,443,652, issued to Edward J. Carey and John B. Geers on June 22, 1948.

The principal object of the invention is to provide a compensating cam roller, resilient in construction, which, when brought into contact with a part to be moved thereby, receives a slight overthrow, to firmly move the latter into proper adjusted position.

With this and incidental objects in view, the invention includes certain novel features of construction and combinations of parts, a preferred form or embodiment of which is hereinafter described with reference to the draw ing which accompanies and forms a part of this specification.

Of said drawing:

Fig. l is a side elevational view of a beam-operated mechanism controlled by a transaction bank of keys.

Fig. 2 is a side elevational view of mechanism adjusted under control of the beam-operated mechanism shown in Fig. 1.

Fig. 3 is an enlarged cross-sectional view of the compensating roller, taken on line 3--3 of Fig. l, and looking in the direction of the arrows.

General description The invention is illustrated applied to a beam-setting mechanism of the class shown in United States Patent No. 2,443,652. In this class of machine, a beam is diiferentially adjusted under control of manipulative devices, which devices are illustrated in said patent as depressible keys. As described in detail in said patent, one end of the beam is difierentially adjusted under control of the keys and then locked in such adjusted position, whereupon the beam is contacted by a cam-operated lever, near the center of the beam, to adjust the free end of the beam in accordance with the adjusted position of the differentially-set end of the beam. The free end of the beam is connected to set a train of mechanism to control certain functions of the machine.

In such beam constructions, it is difficult to fabricate the beam with a high degree of accuracy, with the result that slight variations thereof may cause misoperation.

This is due to the fact that the beam is impinged against a collar in any one of a plurality of positions of the beam, and due allowance must be made between the cam roller which contacts the beam and the collar against which the beam is impinged, so that the beam is forced home with a high degree of accuracy. If the beam is not moved firm ly against the collar, the train of mechanism operated. by the free end of the beam does not properly set the controlling elements set thereby. On the other hand, if the,

cam roller is set too close, certain parts may be damaged.

To avoid these misoperations, the roller for camming the beam is made with a core of rubber, or other resilient material, and is given a slight overthrow, and, when the roller impinges the beam against the collar, its resilient core moves the beam firmly against the collar, with the result that the free end of the beam is always set accurately in any one of its plurality of differentially-set posi tions.

It is well known that such machines as cash registers and accounting machines are capable of adding amounts and printing totals of amounts. In such machines, the amountentering differential mechanisms are controlled in their adding operation by differential elements controlled both by amount keys and by zero stops. In the printing of totals, it is necessary to render the zero stops ineffective to permit the differential actuators to be set under control of the various totalizer elements. The present invention is illustrated in connection with the disabling of the zero stops of the amount differential mechanisms in totalprinting operations, and particularly with the total-printing controls of the machines illustrated in said patent.

Only so much of the mechanism of the patent has been illustrated herein as is necessary to understand the invention. To better point out the various old elements illustrated in the present application, reference numerals are used in the detailed description which correspond to parts of the patent, wherever this is practical.

Detailed description Each amount bank of said Carey and Geers patent is provided with a slide 216 (Fig. 2), which is differentially adjusted under control of an associate totalizer wheel. Normally, the slide 216 is restrained in its home position by a zero stop 211, pivoted on a shaft 212, the pawl having a nose 214, held in the path of a flange 215 by a spring 213. As is well known, when an amount key is depressed, the zero stop pawl 211 is lifted to free the slide 216. When the machine is controlled for total-printing operations, the zero stop pawls 211 must be lifted to free the slides 216, so that they may be controlled by the totalizer element. The zero stop pawls 211 are lifted under control of a transaction differential mechanism during a totalprinting operation by elements illustrated in Fig. 1.

Transaction difierential A shaft 387 (Figs. 1 and 2) has secured thereon a crank 391, connected by a link 392 to a bell crank 393, free on a shaft 264. The link 394 connects the bell crank 393 to a transaction differential beam 395, pivoted on a differential latch plate 397, on which is pivoted a latch 398 to connect the latch plate 397 to a drive plate 396. The differential drive plate 396 is provided with a notch engaged by a stud 245 on an arm 405, free on the rod 247, and said arm 405 is connected to a cam lever 406, also free on the rod 247. The lever 406 bears rollers 407 and 408, which cooperate, respectively, with the peripheries of companion plate cams 409 and 410.

The cam plates 409 and 410 are secured to a main shaft 130, and clockwise rotation of the shaft causes the cams 409 and 410 to rock the lever 406 and the arm 405 first clockwise to rock the transaction differential mechanism also clockwise until such movement is interrupted by a depressed transaction key (not shown), whereupon the latch 398 is disconnected from the drive plate 396 and locked in position in the manner well known in the art, as illustrated in the above-mentioned patent. This positions the latch plate 397 and the upper end of the beam 395 in accordance with the key depressed. Thereafter, the arm 405, when it nears the end of initial, clockwise, movement, engages a roller 411, carried thereby, with an arcuate surface on the beam 395 to force said beam into contact with a collar on the rod 233, to position said beam and, through the linkage 394, the bell crank 393. the link 392,

Patented Dec. 17, 1957 .0 and the arm 391 to adjust the shaft 387 in accordance with the depressed transaction key. Also secured to the shaft 387 is a control segment 385 (Fig. 2), connected to a companion control segment 386 by a link 390. The control plate 386 is pivotally mounted on a stud 388. In this manner, both control plates 385 and 386 are positioned in accordance with the depressed transaction key.

As pointed out in the above-mentioned patent, the control segments 385 and 386 have thereon high spots and low spots in the form of notches, which are adjusted in relation to a stud 384 on a lever 371 to control the timing of the engagement and disengagement of the totalizer for adding or total printing.

After the control segments 385 and 386 have been positioned by the transaction differential mechanisms, cams 380 and 381 (Fig. 2) operate to rock a lever 376, loosely mounted on a shaft 377. The lever 376 is provided with rollers 378 and 379, engaging the cam plates 380 and 381, respectively. The upper end of the lever 376 is provided with a link 375, connected to an arm 373, pivoted on a stud- 374. The lower end of the arm is provided with a stud 372, on which the beforementioned lever 371 is pivoted. The lower end of the lever 371 has connected thereto a link 369, pivoted on an arm 370, loose on a shaft 168. The arm 370 is provided with a stud 691, engaging a slot 690 on one end of a link 689, the other end of which is pivoted to an arm 680 of a yoke 679. The yoke 679 is engaged by a toe 698 of the beforementioned zero stop pawl 211.

As explained in the above-mentioned patent, when the outer surface of the segment 386 is opposite the stud 384, the machine is controlled in totaland sub-total-printing operations. Therefore, initial, clockwise, movement of the levers 376 and 373, under influence of the cams 380 and 381, rocks the lever 371 counter-clockwise, with the stud 384 as a pivot, to shift the link 369 rearwardly to cause the totalizer wheels (not shown) to be engaged with the amount actuators prior to initial movement of said actuators, as explained in said patent. Rearw-ard movement of the link 369 rocks the aim 370 counter-clockwise to shift the link 689 rearwardly to in turn rock the yoke 679 and the zero stop pawls 211 for the amount banks counter-clockwise. Counter-clockwise movement of the pawls 211 disengages their teeth from the flanges 215 of the slides 216 to free said slides for movement under influence of the amount differential mechanisms, so that the said slides will be positioned by the totalizer, as is well known in the art.

As shown in Fig. 2, the control plate 385 is provided with a notch 10 to permit the stud 384 to enter therein when it is desired to rock the lever 371 on the pivot on the right-hand end of the link 369. As pointed out in the above-mentioned patent, when a total key is depressed, the control plate 386 presents an obstruction in the path of the stud 384, so that, during subsequent operation of the machine, when the cams 380 and 381 rock the levers 376 and 373 clockwise, the stud 384, engaging the control segment 386, acting as a pivot, causes the lever 371' to rock counter-clockwise (Fig. 2) to shift the link 369 toward the right. This, through the arm 370, the link 689, the arm 680, and the yoke 679, raises the Zero stop pawl- 211 out of the path of the flange-215 to permit the differential' slide 216 to be positioned under control of the totalizer wheel's.

If the control plate 386 is not accurately positioned, the stud 384 is permitted to-pa'ss beneath the control segment 386, thus preventing the release of the zero stop pawls 211". Such a condition exists when the beam 395 is notpositioned accurately'by the roller 411. If any lost motion exists between the arc' of the beam 395 and the collar 234, the connections including the link 394, the arm 393, the link 392, the arm 39 1, the shaft 387, the control element 385,. the link 390 does not position the. corttrol element 386 as far as necessary to: block movement.

of the stud 384, and during the machine operation the stud 384 passes beneath the control surface of the control plate 386. This condition has been found to exist in manufacturing a machine of the type shown in the abovementioned patent. In order to overcome this difficulty, a roller 411 is constructed with a core 12 (Fig. 3) made of resilient material such as rubber. The core 12 is mounted on a sleeve 13, and the rubber core is fused to the roller 411 and the inner sleeve 13. The inner sleeve 13 is mounted on a stud 14, carried by the before-mentioned lever 405. The cams 409 and 410 are so developed that, in their operation of the levers 406 and 405, the roller 411 is given a slight overthrow, and, when the roller 411 impinges the beam 395 against the collar 234, the resilient core 12 is compressed to firmly impinge the inner arcuatc surface of the beam 395 against the collar 234.

Provision of the resilient core 12 in the roller 411, therefore, provides the means by which the beam 395 is positioned accurately in relation to the collar 234 in any position of the beam, as adjusted by the transaction keys and its controlled differential mechanism, thus assuring that the free end of the beam 395, through the linkage described, will positively and accurately adjust the control plate 386 to position the high spot of the control plate into the path of the stud 384, so that the zero stop pawl will be withdrawn from the flange 215 of the differential slide 216.

In this operation, where the stud 384 slides past the Working surface of the control plate 386, the zero stop pawl 211 is not fully withdrawn, and therefore, when the totalizer elements tend to adjust the slide 216, the slide 216 cannot be positioned according to the amount standing on the totalizer wheels, and the parts are arrested in zero position, thus printing inaccurate totals.

While the present invention, which comprises the roller 411 with the resilient core, is shown applied to a mechanism for withdrawing a zero stop pawl, this is used only as an illustration of one application of the novel roller. The roller may be used in any application where accurate and firm positioning of any part is necessary.

While the form of mechanism shown and described herein is admirably adapted to fulfill the object primarily stated, it is to be understood that it is not intended to confine the invention to the one form or embodiment disclosed herein, for it is susceptible of embodiment in various other forms.

What is claimed is:

1. In a machine of the class described, the combination of a differentially settable member, a beam having one end thereof pivoted to the differentially settable member whereby said one end of the beam is differentially positioned by the settable member, a stopping surface on the beam intermediate its ends, a fixed stop against which the stopping surface of the beam is moved to limit its movement and to position the free end of the beam in accordance with the differential position of the pivoted end of the beam, an operating arm, a cam to operate the arm, a roller on the arm for engaging and moving the beam until the stopping surface on the beam engages the fixed stop to thereby position the free end of the beam in accordance with the setting of the pivoted end of the beam, said cam formed to move said arm an additional extent, a resilient core in the roller which is compressed during the said additional extent of movement of the arm, and control means connected to the free end of the beam so as to be differentially positioned by the beam.

2. In a machine of the class described, the combination of a differentially settable member, a beam having one end thereof pivoted to the differentially settable member whereby said one end of the beam is differentially positioned by the settable member, an arcuate stopping surface on the beam located intermediate the ends of the beam, a stationary sleeve of a diameter corresponding to the radius of the ai cuate stopping surface against which the stopping surface of the beam is moved to limit its movement and to position the free end of the beam in accordance with the difierential position of the pivoted end of the beam, an operating arm, a cam to operate the arm, a roller on the arm for engaging and moving the beam until the stopping surface on the beam engages the stationary sleeve to thereby position the free end of the beam in accordance with the setting of the pivoted end of the beam, said cam formed to move said arm an additional extent, a rubber core in the roller which is compressed during the said additional extent of movement of the arm, and control means connected to the free end of the beam so as to be difierentially positioned by the beam.

References Cited in the file of this patent UNITED STATES PATENTS 413,911 Blanchard Oct. 29, 1889 1,130,463 Barrett Mar. 2, '1915 1,225,442 Konar May 8, 1917 1,778,197 Lord Oct. 14, 1930 2,001,038 Reid May 14, 1935 2,481,812 Beatrice Sept. 13, 1949 

